I'm seeing some strange behaviour with UltraVNC Viewer on my Windows7 64bit machines. I'm also using the SecureVNCPlugin64.dsm v2.3.0.0 as well. I'm using v1.0.9.6.2 across several different machines, WinXP, W2K and Win7... only Win7 64bit seems to have this trouble. (I don't have any 32bit Win7 machines).

When I start UltraVNC Viewer, I get the normal dialogue box up with the "destination" server IP field, options, etc. When I hit the connect button, this window goes away... and then nothing happens! If I check the task manager, I see the lost" vncviewer.exe process. I can kill this without problem.

Every now and then, quite randomly, UltraVNC Viewer does seem to connect properly and I get the password dialogue box up and I can then enter the appropriate password and proceed as normal. I sometimes have to start UltraVNC Viewer half a dozen times or more to get it to work. Each failed attempt to start UltraVNC viewer leaves a vncviewer.exe process running.

I have uninstalled and re-installed v1.0.9.6.2 without resolving the issue. On another Win7 64bit machine I took a step back and installed v1.0.9.5 and still see this same behaviour.

The only thing I can think of that has recently changed is that I have started using Microsoft Security Essentials on these machines... I know that MSE has "issues" with VNC... could this be the cause? Has anyone else here had issues with MSE and UltraVNC Viewer?

I can connect to the UltraVNC servers running on these machines with no problem from WinXP machines... this only seems to affect UltraVNC Viewer.